1. Field of the Invention
The present invention relates to a solid-state image capturing device, an image capturing device, and a manufacturing method of a solid-state image capturing device. More specifically, the present invention relates to a signal obtaining technique which is suitable for being applied to a solid-state image capturing device or the like employing a physical amount distribution detecting semiconductor device wherein multiple unit components having sensitivity as to an electromagnetic wave input from the outside such as light, radiation, or the like, are arrayed, and a physical amount distribution converted into an electric signal by the unit components can be read out as an electric signal. For example, the present invention relates to applying to a solid-state image capturing device capable of image capturing using a wavelength component (e.g., infrared light) other than visible light.
2. Description of the Related Art
Physical amount distribution detecting semiconductor devices made up of multiple unit components (e.g., pixels) being arrayed in a linear or matrix shape which have sensitivity as to physical amount change such as an electromagnetic wave input from the outside such as light, radiation, or the like have been employed for various fields.
For example, in the field of picture devices, CCD (Charge Coupled Device) type or MOS (Metal Oxide Semiconductor) or CMOS (Complementary Metal-oxide Semiconductor) type solid-state image capturing devices, which detect change in light (one example of an electromagnetic wave) which is an example of a physical amount, have been employed. These read out a physical amount distribution converted into an electric signal by unit components (pixels in a solid-state image capturing device) as an electric signal.
For example, a solid-state image capturing device detects an electromagnetic wave to be externally input such as light, radiation, or the like, using a photodiode, which is a photoelectric conversion element (receiving element; photo sensor) provided in an image capturing portion (pixel portion) which is a device portion, generates and stores signal charge, and reads out this stored signal charge (photoelectron) as image information.
Now, in the event of an arrangement wherein a color image is obtained, employing an image sensor is a current mainstream wherein a color filter such as transmitting a particular wavelength component alone is disposed for each pixel, and necessary color components are restored with a set of multiple pixels, thereby distinguishing a color.
Specifically, as for a set of color filters, a color is distinguished by a color array employing subtractive color filters of red (R), green (G), and blue (B) which are three primary colors, and a semiconductor layer configured to detect light is provided under each color filter, thereby detecting each of three primary color lights separately which have been transmitted through filters. Also, employing an array serving as a luminance signal obtaining array wherein white (Y), red (R), green (G), and blue (B) are combined can be considered. These arrays are all called Bayer arrays.
With a solid-state image capturing device employing a single-device color system, each pixel thus has only a single color component, so for example, interpolation processing is performed employing the color information of surrounding pixels, whereby demosaic processing for restoring color components necessary for each of the pixels is performed (see Japanese Unexamined Patent Application Publication No. 04-088784).
On the other hand, in recent years, an arrangement has also been considered wherein a new application is realized by detecting components other than visible light components, which cannot be realized in the case of detecting only visible light components.
As for one example, the present assignee has proposed an arrangement wherein a visible light component and an infrared light component are simultaneously detected, and the detected infrared component is employed, thereby realizing high sensitivity, and suppressing the infrared light component from leaking into the visible light component, even with a single-device system.
However, we have found that with an existing solid-state image capturing device, a semiconductor layer where a detecting unit such as a photodiode is disposed principally has a device configuration optimized for detection of visible light, which makes it difficult to obtain sufficient performance since, the detection sensitivity of infrared light component is low with an arrangement for simply detecting a visible component and an infrared light component at the same time using such a semiconductor layer.